You need administrative permissions to roll back Connectors.
Rollback automatically reinstates the most recent version prior to the currently installed version. You cannot do a remote rollback on a connector to other than the previously installed version.
Check with Micro Focus Customer Support for ArcSight products on the SmartConnector version to which you can roll back.
Where: Navigator > Resources > Connectors
Select the connector you want to upgrade.
Right-click and select Send Command > Upgrade > Rollback from the context menu.
As the rollback proceeds, the connector shows as down and then running again in the resource tree. You can check the logs for the connector to determine if the rollback succeeded. (Send Command > Tech Support > Get 'agent.properties' and Get Upgrade Logs.)